Video courtesy of NoCo 5

POUDRE CANYON - Fire authorities have begun mandatory evacuations of a neighborhood south of Bonner Springs Ranch Road northwest of Fort Collins as the 5,000-plus-acre Hewlett Fire encroaches on homes.

Residents are being told that an evacuation center is open at Cache La Poudre Middle School at 3515 W. County Road 54G in Laporte.

With shifting winds and rugged terrain, the Hewlett Fire raced across the landscape Wednesday, quintupling in size and nearing more neighborhoods.

The fire is now estimated at 5,090 acres near Poudre Park, Glacier View, Bonner Peak and Bonner Springs subdivisions.

Residents of those areas not currently being evacuated have been told to prepare to leave at a moment's notice.

The fire sparked about 1 p.m. Monday near the Hewlett Gulch trail and has grown steadily. It now stretches east to Seaman Reservoir and west to within a half mile of Glacier View and remains west of the North Fork of the Poudre River and North of Poudre Canyon Highway (Colorado 14), according to the U.S. Forest Service.

The canyon highway has remained open during the fire, but it will be closed this afternoon for a three-hour period while firefighters burn back a half-mile stretch onto the fire near the Greyrock footbridge to secure the fire line down to the river. But as of Thursday morning, containment was still estimated at 5 percent.

Smoke from the fire increased Wednesday and Thursday, reaching as far south as Loveland. Health officials warn residents of the dangers of inhaling smoke laden with particles from a wildfire and urge them to stay indoors and avoid physical activity outside with smoke in the air.

The Larimer County Health Department has issued a health advisory regarding air quality. Coyote Ridge Elementary and Cottonwood Plains Elementary Schools are taking safety precautions and children are being kept indoors during recess today. The air quality at all Thompson School District schools on the north side is being monitored by school staff, according to Wesley Fothergill, communications director with Thompson Schools.

Nearly 400 firefighters are battling the blaze with help from two helicopters and a tanker plane.

Investigators have said a person started the fire, but no additional details have been released.